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Sig 1/3 scale Spacewalker & Zenoah engine question

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Sig 1/3 scale Spacewalker & Zenoah engine question

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Old 10-03-2018, 01:15 AM
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Default Sig 1/3 scale Spacewalker & Zenoah engine question

Would an older Zenoah 74cc twin cylinder engine be considered too large for this airframe?
Iím an experienced Rc flyer but havenít used gas engines before, hence I cannot really assess the level of compatibility here...
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Old 10-03-2018, 04:04 AM
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The first 1/3 Spacewalker that I saw fly, was powered by a G-38. It flew in a "scale" fashion. These days, I see larger engines in them. I would think that your Zenoah twin would be a good match.
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Old 10-05-2018, 05:28 AM
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I think a 74 is too much. Not saying it can't be made to work but..... Tom, you saw one fly scale on a 38. Sig recommends up to a 50. 74 just seems excessive to me. Unless you want unlimited vertical.

Pick up an OS Pegasus 320 (53cc). Bet that would look sweet in that air frame. And you wouldn't have to build a dummy engine!
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Old 10-05-2018, 06:07 AM
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Originally Posted by Appowner View Post
I think a 74 is too much. Not saying it can't be made to work but..... Tom, you saw one fly scale on a 38. Sig recommends up to a 50. 74 just seems excessive to me. Unless you want unlimited vertical.

Pick up an OS Pegasus 320 (53cc). Bet that would look sweet in that air frame. And you wouldn't have to build a dummy engine!
EF asked about the Zenoah twin. I agree that it is more than required, power wise, but I feel that it's a suitable choice.

The G-38 powered models flew like full scale Cubs. A dive was necessary to perform a loop.

My 1/3 Spacewalker has yet to be maidened, so I can't comment on it's performance. . It is powered by a Sachs 4.2. It balanced perfectly with that engine. The 774 may be good choice, based on it's weight.
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Old 10-05-2018, 06:08 AM
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Isnít a 70-75cc twin cylinder engine roughly equivalent to a 50cc single cylinder engine power-wise?
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Old 10-10-2018, 05:58 PM
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Originally Posted by EF View Post
Isnít a 70-75cc twin cylinder engine roughly equivalent to a 50cc single cylinder engine power-wise?
I suppose that depends on the individual engines . Normally a twin of the same displacement as a single of same brand may be slightly lower in rpms than that of the single but not by much. They should turn the same props within a couple hundred rpm of each other . The twin will definetly be smoother than the single
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Old 10-11-2018, 10:23 AM
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I wouldn't recommend the Zenoah twin simply because it weighs so much ..... and I've flown the Zenoah twins a lot! Seems like severe overkill for the Spacewalker though they do run very smoothly. If you tend to build tail heavy, it may be a good choice though. The OS Pegasus looks great but is anything but a sparkling performer when it comes to power. One of the large Saito or OS twins offer better performance than the Pegasus. A more conventional engine would be my choice when it comes to ease of operation and just generally easier to live with.
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Old 10-11-2018, 10:38 AM
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EF The 774 is no powerhouse by any means but will definitely pull the Spacewalker around with authority if its running properly. I say if this is the engine you have use it . If you are purchasing an engine then go with a newer offering that will fit the Spacewalkers needs and also be a viable choice for future plane projects as well .
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Old 10-11-2018, 11:23 AM
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Thanks for the informative replies!
I havenít bought an engine yet so will get something more suitable than the Zenoah.

How about the DLE 40 twin?
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